1. Field of the Invention
The present invention is related to packframes employing supporting frames of tubing or other hollow structural members as used by hikers for supporting their packs and to improvements in those packframes by utilizing the empty space within said tubing, together with any desirable modifications of the configuration of the tubing, for storing, transporting and pressurizing fluids in order to achieve certain advantages in weight, balance, space utilization, durability, and protection from odor.
2. Description of the Prior Art
Of all the commodities carried by hikers for their comfort and survival, fluids are among the heaviest. The fluids most commonly carried are water and fuel, weighing about 8.3 pounds per gallon, plus the weight of the containers.
The daily consumption of water is usually one gallon per day or more, constituting a weight of about six times that of food consumed per day. The total amount of water carried depends upon availability of supply along the trail, the number of days to be hiked, and the strength and endurance of the hiker. Whenever water is plentiful the quantity carried may perhaps be only a quart, but in desert areas it may be considerably more.
The water is usually placed in metal or plastic canteens and carried within the pack for convenience and weight economy of the container. A minority of hikers carry them separately, in cases, attached to belt or hanging by straps from the shoulder. Placing the canteens inside the pack uses up a relatively large amount of space, thus requiring larger packs than otherwise would be necessary. The approximately 280 cubic inches of space for each gallon of water and container equals 10 percent of the capacity of a popular-size pack containing 2,800 cubic inches of space.
Carrying water in a pack also creates three major problems of weight distribution for the hiker. First, it requires him to lean forward to compensate for the backward pull of the water's weight on his back. Second, because of the height at which the water containers are carried in the pack, as well as the weight-shifting tendency of the water within both container and pack, the hiker has less control over his balance, especially when traveling uneven terrain. Carrying the water high in the pack and close to the body partially offsets the first problem but aggravates the second, and vice versa. Third, care is required, as water is consumed, that the remaining supply is not located mostly on one side of the pack so as to create an imbalance in weight.
Another disadvantage of carrying water inside the pack is the inconvenience of access, requiring the hiker to remove the pack from his back and open it each time he wants a drink, which tends to be frequent because of the energy expended in hiking.
Although the wilderness environment was once relied upon to provide fuel for cooking, conservation now requires that most backpackers carry stoves, many of which require a liquid petroleum-base fuel, either kerosene or white gasoline. This fuel is normally carried in one or more metal containers placed inside the pack. Carrying the fuel in the pack creates similar problems of space, weight, and balance as in the case of water, plus another which is particularly inconvenient, leakage and odor. Despite all efforts, the fumes usually penetrate food, clothing, and other supplies.
Packframes have improved in recent years from crude, heavy wooden frames to light-weight (usually aluminum-alloy) frames with structural variations according to the size and design of the pack to be carried and individual needs for attaching additional equipment to the frame such as sleeping bags, tents, etc. The strength of the packframes varies, with an inherent conflict of strength versus weight always being a factor in their design. The single objective of the packframe has been that of supporting the pack itself while carried by a hiker, plus any sufficient strength necessary to maintain its shape during normal handling after removal by the hiker. In practice the compromises made in order to lower the weight of the packframe have resulted in fragility which often leads to bent and damaged frames. However, this is a situation which can be improved if the packframe is made to serve one or more additional objectives and to concomitantly offer advantages to compensate for any increase in packframe weight, as proposed by this invention.
Canteens, except for the utilization of new materials such as plastic, have changed relatively little over the years, and remain essentially bottles. They serve no other purpose than containing fluids.